I have tingling in my left foot and leg, but I don't have a vitamin b defecientcy. How much vitamin b 12 from a supplement can I take that's harmless but helpful (I have been taking 1000 mcgs for two weeks).

1000mcg is fine. You can even do it 3 times a week instead of every day. About 10mcg is actually absorbed each dose, if you do it correctly on an empty stomach.

But most people with nerve symptoms can use more B12 it is thought. Dr. Snow mentions this in his medical paper.
He feels some people may just need more.
http://neurotalk.psychcentral.com/post698522-70.html

There is no upper limit for B12 set by the FDA. At this time there has never been a case of toxicity.

Thank you Ms D you are a blessing and I appreciate your help and knowledge. I see my neurologist in a month to undergo further testing. I think I may have had a transient ischmeic attack from my cocaine binge. The nerves in the left side of my toes don't feel really tight and the tingling is mild so maybe I could be healing (or maybe not). I'm 28yrs old and I'm clean of all drugs since my relapse and hope to start truck driving school if all goes well with my toes/leg. Is it better to take b12 sublingual or regularly???

You can chew up the sublinguals and swallow with water.

Some people get irritated mouth membranes from sublinguals.
The absorption orally is good, and studies show that.
Just do it on an empty stomach, and no food for an hour after
for best absorption. It is passively absorbed in the small intestine.

I had some irritation at first, but stopped putting it near my gums and keep it under my tongue. I do not have any irritation under the tongue.

My personal, unscientific, opinion it that I prefer to do it sublingually and not chew it, I just feel it works better. Again, that is my own belief. As long as I am able to to it that way, I will.

Also, I am not deficient in B12 and I take 5mg a day.

Thank you Stacy.

Some of the research I have read suggests that the longer you can keep the B12 under the tongue the better the results. There is even some timed studies with different name brands, as each are different.

The Jarrow lasts much longer than the Enzymatic Therapy for me. The suggested length is 45 minutes, which is about the time I can keep Jarrow. Of course it is all dependant on things like how much you move it around in your mouth, how much saliva, if you drink during it, etc.

Enzymatic Therapy will only last 30 min if I am lucky, sometimes 20. Jarrow is a more chalky pill and ET is not so chalky, has a sweeter taste and is a smaller pill.